427 
As the models have altogether had an elevation control point in 
every corner these locations have been used in the theoretical determina 
tion of the accuracy of the elements of the absolute orientation. The 
notations and locations are chosen according to fig. 3. The corrections 
of the orientation elements can be observed as direct functions of the 
elevation errors in the control points [14] 
dh ™ 
(lh o = 
dy] =z 
d£ 
[XY] [Ydh] — [Xdh] [YY] 
[XX] [YY] — [XY] 2 
[XY] [Ydh] — [Ydh] [XX] 
13) 
[XX] [YY] — [XY] 2 
where X and Y are the coordinates from the center of gravity of the 
control points. After inserting the points 11, 91, 19 and 99 into (13) 
the following results are found. 
1 
dhn = 
4 
(dhix + dh 91 + dh 19 + dh 99 ) 
dr] — 2p (— dh lx + dh 91 — dh 19 + dh 99 ) (14) 
d£ = ^ (dhn + dh 91 — dh 19 — dh 99 ) 
The corresponding weight coefficients are 
1 
4 
1 
b 2 
1 
(5 lioho = 
Q y)ri — 
(15) 
Qtf = 
4d 2 
The errors of the elements of the relative orientation have the follow 
ing influence upon the elevation errors 
hy h 2 + x 2 
b 
dh = 
(d k 2 — d/q) 
dpi + 
+ 
h 2 + (x — b) 2 
d<p 2 
(x — b) y 
IOJ9 
(16)